Tool bit and holder therefor



.Sept. 21, 1948. H. M. SHERIDAN 2,449,823

TOOL BIT AND HOLDER THEREFOR Filed June 7, 1945 IN VENTOR.

Bk W 7- M R; EFFORNEY.

Patented Sept. 21, 1948 UNITED STATES PATENT OFFICE TOOL BIT AND HOLDER THEREFOR Henry M. Sheridan, Erie, Pa. Application June 7, 1945, Serial No. 598,040-

4 Claims.

This invention relates to replaceable tool bits and holders therefor.

The objects of the invention include the provision means for removably securing cutting tips of carbide cobalt or th like in a tool holder so as to avoid the expense of a solid one piece tool.

Another object of the invention i to provide a tool holder having new and improved locking means whereby the bit may be rigidly secured within the holder without danger of accidental displacement or vibration with respect to the holder.

A further object of the invention is to provide a holder in which independent securing clamps are each provided with means to relieve the cutting thrust applied thereon.

Another specific object of the invention is to provide a new and improved cooperation between holders, clamps and bits thus to achieve a more positive and rigid securement of the bit in its adjusted relation to the holder.

Other objects and features of the invention will be apparent from a consideration of the following specification taken in conjunction with the accompanying drawing, in which:

Fig. 1 is a top plan view of one of the preferred embodiments of the present invention.

Fig. 2 is a side elevation of that form of the invention shown in Fig. 1;

Fig. 3 is an end elevation of the bit and holder shown in Figs. 1 and 2, and

Fig. 4 is a detailed top plan view of a modified form of the invention.

The herein disclosed embodiment of the present inventive concept may be generally defined as comprising a shank terminating in a bit platform provided with an integral raised bit seat and a pair of bit clamps independently secured to the shank. The inner face of the platform being defined by a wall formed by the shank which is angularly disposed transversely in a vertical plane. At least one of the clamps abut the angular surface whereby a wedging action is imparted to the clamp to assist in the securement of the bit.

In the drawings, the present embodiment of the invention comprises a body or shank Ill here shown as of simple rectangular formation. One end of the body constitutes a bit holding head indicated by the member I I. The upper surface of the head II is stepped down from the upper surface of the body I and constitutes a pair of parallel coplanar surfaces, one being a bit table while the other may be serrated, preferably longitudinally a shown in Fig. 3 and receives the longitudinal clamp of a pair of longitudinal and trans- Verse clamps I2 and I3, respectively. A bit I4 is adapted to be mounted on the bit table. The bit is recessed to receive a bit seat I5, the internal face of which is angularly disposed both in a vertical and transverse plane thereto engage the bit to secure the same against accidental outward movement either transversely or longitudinally from the table.

The longitudinal clamp I2 which preferably conforms in configuration to the surface of the head not occupied by the bit is provided with a pair of elongated transverse slots I6 through which securing screws I! extend and threadedly engages the head II to secure the clamp in adjusted position. The heads of the screws II are preferably seated within .an enlarged portion of the slots so as to leave the upper surface of the assembly free from projection. However, securing screws extending upwardly through the head II to engage the clamp may be used as an equivalent securing means. The longitudinal inner face I 8 of the clamp I2 is vertically inclined to cooperate with and retain thereunder a similarly inclined inner longitudinal side face of the bit I4. The inner transverse end of the clamp I 2 is also inclined to conform with a similar inclination formed by the end face of the shank above the bit table and clamp surface so that the end face of the clamp I2 similarly overlies the cooperating inclined face I9.

The transverse clamp I3 which is of a length substantially equal to the width of the bit I4 is also provided with an inner end face vertically inclined to conform with the surface I 9. Its opposite or bit engaging surface 20 is similarly inclined vertically to lie over and secure the similarly inclined inner face of the bit. The surface 20, however, is also inclined transversely as well as vertically and engages a similar inclination transversely of the inner end face of the bit. A bolt 2| is provided for securing the clamp I3 in adjusted position.

From this construction, it will be seen that the bit I4 is securely locked in position in the holder, the overhanging bevels or each clamp provide a camming action resisting an upward thrust which may be imparted to the .bit and at the sam time looking the bit against the shoulder I5. It will also be noted that the transverse angularity of the front surface of the clamp I3 and the transverse angularity of the shoulder I5 will be effective in biasing any direct inward thrust towards the side clamp I2. The adjustability of the side clamp by virtue of its slots I6 and the serrations permits a transverse adjustment of the bit to compensate for wear and repeated grindings.

In that form of the invention shown in Fi 4, the longitudinally extending clamp 22 terminates in obliquely inclined ends 23 and is provided with similarly obliquely inclined slots 25 through which the securing screws 25 extend. The transverse clamp 26 is also provided with one cooperating inclined end 27. In this interpretation of the inventive concept the longitudinal clamp 22 does not abut the inclined wall 28 of the head,

however, a forward thrust is imparted to this clamp by the slots 26 and thus the same biasing of a direct transverse inward thrust is achieved whereby such thrlust will have imparted thereto a longitudinal force vector.

In carrying out the present-invention, it will be understood that many various modifications may be resorted to. For instance, it may in some instances be desirable tolextend the shank angulariy with respect to the-head and it may be also desirable to provide various types-of ribs or serrations between the .tool bit and the clamps or the tool bit and the head or between the clamps and the head. It will also be understood that'various modified types of securing means may be used for attaching the clamp to the head. Such departures from the specific exemplifi cation of the present invention are not deemed a departure from the spirit or scope of the invention as outlined in the appended claims; 2

What I claim is: l 4- 1. Inna tool holder, a solid elongated substantially'rectangular shank, a seat at one end of said shank having an inner end defined by a transverse shank wall, a bit shoulder formed on said seat-and extending in a transverse crosswisedirection thereof and spaced outwardly from said transverse shank wall, and a pair of independently 'r'rnounted and independently secured first and second bit clamps positioned on said seat, said first clampshaving a straight longitudinal face adapted'to engage the side wall of a tool bait and an'in'ner end face engaging said trans! between a dovetail pocket for securing the tool bit.

3. A holder as defined in claim 1 in which the coating faces of the bit shoulder and the outer end face of the second clamp are each oppositely inclined with respect to each other in both longitudinal and transverse directions to define therebetween a downwardly opening and inwardly opening pocket dovetailed in both longitudinal and transverse directions.

4. A ho lderas. defined in claim 1 in which the straight longitudinal face of the first clamp is inclined outwardly from top to bottom to overlie a tool bitmounted on said seat.

' HENRY M. SHERIDAN.

REFERENCES CKTED The following references are'of record in the file of this patent? V UNITED STATES PATENTS Number Name I Date 1,045,512 Carr Nov. 26, 1912 1,537,957 Marshall May 19, 1925 2,150,561 Reaney Mar. 14, 1939 2,165,571 Ortegren July 11, 1939 2,166,826 Shepherd July 18,1939 2,314,665 Specht Mar. 23, 1943 FOREIGN PATENTS Number Country Date France s, y Feb. 1'5, 193'? 

